Binder for cutting particles of abrasive tool

ABSTRACT

A binder for cutting particles of an abrasive tool comprising a high-molecular component including butadiene-nitrile rubber in the amount of 100 parts by weight in combination with phenolformaldehyde resin in the amount of 10-30 parts by weight and with polyvinylchloride resin in the amount of 5-70 parts by weight, while the materials used for vulcanization, solidification, plasticization and stabilization of the ingredients of the high-molecular component include the following components taken in parts by weight sulphur 1.5-40.0zinc oxide 3.0-20.0hexamethylenamine 0.5-1.5plasticizers of polyvinylchloride resin 5.0-40.0stabilizers of polyvinyl-chloride resin 0.5-3.0.

United States Patent 1191 Bakul et a1.

[451 June 18,1974

[ BINDER FOR CUTTING PARTICLES 0F ABRASIVE TOOL [76] Inventors: Valentin Nikolaevich Bakul, Kirova u1., 34-a, kv. 12; Esfir Salimanovna Rabinovich, Krasnopolskaya ul., 20/15, kv. 25; Jury Alexandrovich Yakovchuk, Lesi Ukrainki bulvar, 3, kv. 42, all of Kiev, U.S.S.R.

22 Filed: July 5, 1972 21 Appl. No.: 269,136

Related US. Application Data [63] Continuation-impart of Ser. No. 70,589, Sept. 8,

1970, abandoned.

521 U.S.Cl. 260/19 11, 260/45.95 R, 260/826, 4 :P260/846,260/847 51 1111. C1 C08g 5/20 58 Field of Search ..260/846,826, 194,845, 260/847, 45.95 R

[56] References Cited UNITED STATES PATENTS 11/1953 Berger ..260/19 UA 10/1966 Giller 266/19U FOREIGN PATENTS OR APPLICATIONS 514,858 7/1955 Canada 260/19 U 613,073 11/1948 Great Britain 266/19 U Primary ExaminerDonald E. Czaja Assistant Examiner-William B. Parker Attorney, Agent, or Firm-Holman and Stern [57] ABSTRACT sulphur .5-40.0 zinc oxide 3,0-20.0 hexamethylenamine 0.5-1.5 plasticizers of polyvinylchloride resin 5.0-40.0 stabilizers of polyvinylchloride resin 0.5-3.0.

5 Claims, N0 Drawings BINDER FOR CUTTING PARTICLES OF ABRASIVE TOOL This application is a continuation-in-part of application Ser. No. 70,589, filed Sept. 8, 1970, now abandoned.

The present invention relates to the field of manufac- I The present invention can be most successfully used for making diamond polishing bands designed, for example, for treating journals of crankshafts of automobile and tractor engines.

Well known in the art are binders for cutting particles of an abrasive tool including a high-molecular component and materials'used for vulcanization, hardening, plasticization and stabilization of the ingredients of the high-molecular component.

In the known binders for cutting particles of an abrasive tool the high-molecular component is a combination of butadiene-nitrile rubber with phenolformaldehyde resin, while the materials used for vulcanization and solidification of these ingredients of the high-molecular component consist of sulphur, zinc oxide, magnesium oxide, 2,2-dithio-bis-benzothiazole, Z-mercaptobenzothiazole, tetramethylthiuram disulphide, hexamethylenamine.

These binders provide'for strong anchoring of the cutting abrasive particles, however, the binders themselves and the abrasive layers on the base thereof have a low plasticity and, therefore, are disadvantageous from the technological point of view: they are poorly rolled, calendered and shaped in the process of pressing. in this case, the addition of a plasticizing agent into the high-molecular component to avoid the abovementioned disadvantages presents considerable technological difficulties.

The above disadvantages do not permit the binder to have a necessary elasticity and flexibility. Furthermore, the abrasive-containing layer made on the base of the known binders of the above-said types exhibits a poor wear resistance and is worn out before the high cutting properties of the abrasive tool, e.g., diamond, are completely utilized.

in the other known binders for cutting particles of an abrasive tool the high-molecular component is a combination of butadiene-nitrile rubber'with a polyvinylchloride resin, whereas the materials used for vulcanization, plasticization and stabilization of the said ingredients of the high-molecular component consist of sulphur. zinc oxide, magnesium oxide, 2.2-dithio-bisbenzothiazole. 2-mercaptobenzothiazole, tetramethyltiuram disulphide. dibutylphthalate, calcium stearate.

In these known binders the high-molecular component is easily mixed with plasticizers and, as a result, these binders feature good technological properties. However, these binders have a short life in operation, because they hold the cutting particles poorly due to their low adhesiveness.

An object of the invention is to eliminate the abovementioned disadvantages.

The basic object of the invention is to develop a binder for cutting particles of an abrasive tool comprising such a high-molecular component which would provide for strong fixing of the cutting particles, would have a high wear resistance and would be practical to make.

This object is attained by providing such a binder for cutting particles of an abrasive tool in which, according to the invention, the high-molecular component consists of butadiene-nitrile rubber in the amount of parts by weight in combination with novolak phenolformaldehyde resin in the amount of 10-30 parts by weight and polyvinylchloride resin in the amount of 5-70 parts by weight, whereas the materials used for vulcanization, solidification, plasticization and stabilization of the ingredients of the high-molecular component consist of the following ingredients (in parts by weight):

sulphur 1.5 to 40.0 zinc oxide 3.0 to 20.0 hexamethylenamine 0.5 to L5 plasticizers of polyvinylchloride resin 5.0 to 40.0 stabilizers of polyvinylchloride resin 0.5 to 3.0

ltis expedient to use dibutylphthalate as a plasticizer of polyvinylchloride resin and calcium stearate as a stabilizer of this resin.

The most advantageous solution of the problem is achieved in the case when the proposed binder for cutting particles besides the ingredients given hereinbelow in parts by weight:

It is also advantageous that proposed binder for cutting particles of an abrasive tool, besides the ingredients given in the following parts by weight:

butadiene-nitrile rubber 100.0

- novolak phenol-formaldehyde resin l0.0'-20.0 polyvinylchloride resin 100-60.0 sulphur 20.0-30.0 zinc oxide 10.0-20.0 hexamethylcnamine 0.5-1.0 dibutylphthalate 25.0-35.0 calcium stearate 0.5-1.0

also comprises magnesium oxide 8.0-1 3.0 2.2-dithio-his-benzothiazole l.8-2.3

It is preferable to use such a binder for cutting particles of an abrasive tool which, in addition to the ingredients given hereinbelow in parts by weight, i.e.:

butadiene-nitrile rubber 100.0 novalak phenol-formaldehyde resin 20.0-25.0 polyvinylchloride resin S.0l0.0

" -Contmued sulphur 35.0-40.0 zinc oxide l0.()-20.() hexamethylenaminc l.0- l .3 dibutylphthalatc 5.()-l().0 calcium stearate 0.5-1.0

also comprises magnesium oxide 23.0-13.0 stearic acid [.0-1.5 coumarone resin 5.0-10.0 2.2-dithio-bis-benzothiazolc 1.8-2.3 tetramethylthiuram disulphide 0.5-0.7

Due to the above-mentioned compounds the proposed binder for cutting particles of an abrasive tool provides for strong anchoring of the cutting particles, has a high wear resistance and ensures wide technologi cal facilities which make it possible to use this binder for making an abrasive tool with a variety of properties: from a soft, elastic and flexible tool to a hard and rigid one.

The invention is further described by way of example with a proposed table of compounds of the binders for cutting particles of an abrasive tool.

In the proposed binder for cutting particles of an abrasive tool the high-molecular component, according to the invention. consists of butadiene-nitrile rubber in the amount of 100 parts by weight in combination with novolak phenol-formaldehyde resin in the amount of 5-70 parts by weight, while the materials used for vulcanization, solidification, plasticization and stabilization of the ingredients of the high-molecular component and included into the compound of the binder comprise the following ingredients taken in parts by weight sulphur 1 5-40.() zinc oxide 3.0-20.0 hexamethylcnaminc 0.5-l.5 plasticirer of polyvinylchloride resin 5 ()-40.0 stabilizers of polyvinylchloride resin 0.5-3 0 To accelerate the process of vulcanization it is expedient to introduce additions of activators of the accelerators of vulcanization zinc oxide and magnesium oxide, additions of the accelerators Z-mercaptobenzothiazole and tetramethylthiuram disulphide. while in order to facilitate the process of mixing all components .of the binder on rolls and for better dispersion of the cutting particles within the binder in the process of milling, besides the dibutylphthalate, coumarone resin and stearic acid are added.

In the process of mixing of the components of the binder on the rolls and during the vulcanization of the binder mixed with the cutting particles, the rubber interacts with the novolak phenol-formaldehyde resin. The polyvinylchloride resin accelerates this process. Simultaneous application of the rubber, novolak phenol-formaldehyde resin and polyvinylchloride resin in the binder in the above-said ratios makes it possible to obtain binders having a high wear resistance, capable 'of strongly retaining the cutting particles and being technologically convenient during the operations of milling, calendering, and shaping in the process of vulcanization.

By? varying the amount of novolak phenolforrnaldehyde and polyvinylchloride resin and other components relative to the amount of rubber, it is possible to obtain the binders having different properties: from soft and elastic to hard and rigid. Any increase of the content of novolak phenol-formaldehyde resin, sulphur and zinc oxide in the binder results in an increase of the rigidity of the binder. On the other hand, any increase of the amount of polyvinylchloride resin in conjunction with its plasticizer at a low content of sulphur and zinc oxide contributes to production of soft, elastic and wear-resistant binders.

The plasticizer of the polyvinylchloride resin consists of dibutyiphthalate while the stabilizer of the same consists of calcium stearate.

Due to a wide range of the properties of the binder, the abrasive tool whose cutting particles are fixed in these binders features wide technological facilities.

An abrasive tool made on the soft elastic binders in the process of polishing provides for a high smoothness of the treated surface (Ra 0.02-0.006 microns) at a negligible removal of the material (in the order of 2-3 microns). The tool made on the rigid binders provides for smoothness of the treated surface up to Ra 0.63-0.20 microns at an increased removal of the ma- TABLE of compounds of binders for cutting particles of abrasive tool Components Parts by weight No. l No.2 No.3 No.4

High-molecular component I. Butadicne-nitrile ruhhcr 2. Novoluk phenol-formaldehyde resin 3. Polyvinylchloride resin Sulphur Lilli disulphide Z-mercaptobcnzothiazolc 2.2-dithio-bis benzothiazole Tctramcthylthiuram TABEE-ContimiEd r of compounds of binders for cutting particles of abrasive tool Components Parts by weight No,l No.2 No.3 No.4

8. Zinc oxide 4.0 l5.0 l5.0 l5.0

9. Magnesium oxide l0.0 l0.0 l0.0 l0. Hcxamethylcnamine 0.75 0.75 0.75 l .25

I I. Dibutylphthalate 30.0 30.0 30.0 5.0

12. Stearic acid L 13. ,v Coumaroneresin 5.0

T4. Calcium sterate 0.5 0 0.5 0.5

Total: 203.75 243.25 253.25 2l0.35

EXAMPLE 1 The compound of binder No. 1 given in the Table is recommended for making the soft high-elasticity binders used as a binding agent for cutting particles of an abrasive tool intended for polishing materials to a high degree of smoothness of the treated surface (Ra 0.02-0.006 microns).

Such a binder is used, for example, in manufacture of diamond elastic polishing disks designed for making metallographic and mineralographic microsections.

EXAMPLE 2 Binder compound No. 2 given in the table is recommended for theelastic binders of an increased hardness used in preparation of a cutting layer of an abrasive tool employed when polishingmaterials to the surface smoothness corresponding to Ra =0.08-0.025 microns but at somewhat higher removal of the treated material (3-4 microns).

This binder is used, for example, in manufacture of diamond emery cloth designed for polishing semiprecious stones.

EXAMPLE 3 EXAMPLE 4 Binder compound No. 4 given in the Table is recommended for preparing the rigid binders of the ebonite type used in makinga cutting layer of an abrasive tool designed for treating materials to the surface smoothness corresponding to Ra 0.63-0.20 micron while removing the treated material for 7-10 microns.

Such a binder is used, for example, in making diamond bands employed. for treating various steel members.

The above-said. binders can be used for an abrasive tool applied on a carrier, e.g., a fabric in the form of a band, emery cloth, disks, or without any carrier base, i.e., grinding-and-polishing wheels, bars for finish honing, etc.

On making the bands, emery cloth, disks, the abrasive-containing layer consisting of the binder with dispersed cutting particles is anchored on a carrier by means of hot pressing and vulcanization in a usual way.

The wheels, honing bars and similar tools are usually made by means of hot moulding and vulcanization of the abrasive-containing layer in press-moulds.

f'lhe tool made with an abrasive-containing layer on the. binders according to the invention provides for a high quality of the treatment and is characterized by high operational properties.

Thus, the use of the elastic diamond disks based on compound No. 1 (see the Table), as a binder makes it possible to obtain such a high quality of the surface of some materials like palladium, bimetal materials and various alloys, which was unachievable earlier through the use of the known tools. These disks are characterized by extremely high resistance and by stability of their properties. A set consisting; of three disks of 200 mm in diameter comprising diamonds of various granularity can be used for making 3,000 to 6,000 highquality metallographic microsections of steels and hard alloys of various grades; each having an area of 1.5 to 2.0 cm. The resistance of the disks made on the base of this binderexceeds the resistance of the same disks made on the base of conventional binder at least by a factor of 1,000.

The experiments have shown that when using the compound of binder No. 3, according to the present invention, itis possible to make diamond bands having high resistance and stability and intended for treating steel members. For example, a. single band with the dimensions of a diamond-containing layer of 55.0 X 43.5 X 0.8 is suitable for polishing 40,000 to 80,000 journals of steel crankshafts of automobile engines against 500 journals in the case of using the conventional bands of the same size made on the base of the known binders.

The high resistance of the tool and stability of its properties make it possible to mechanize and automate the processes of grinding, and polishing effected with the aid of such a tool. in addition, it is possible to modernize the grinding-and-polishing equip'ment by eliminating the units intended, for example, for reelingand unreeling the band and for automatically transferring the band after the treatment of each member.

Thus, the binders according to the present invention, make it possible to produce an abrasive; layer having a high wear resistance, high capacity for holding cutting abrasive particles and good technological properties;

therefore, such a layer is featured by high operational said binder further comprising: charactensucsl- 2-mercapiohenzothiuzolc 1.5- .0 what we clalm tetranicthylthiurzim disulphide 0.5().8

l. A binder for cutting particles of an abrasive toolcomprising a hi h molecular component, id hi h 4. A binder as claimed in claim 1 wherein said high lecular component consisting of lOO parts by weight of molecular Component and Said materials r Presem in butadiene-nitrile rubber, 10 to 30 parts by weight of a the following pr p rtions in parts by weight:

novolak phenolformaldehyde resin and 5 to 70 parts by huwdicnmmflu rubber I 00 0 weight of polyvinylchloride resin, and materials for vulnovolak phenol-formaldehyde resin l0 .0-20.0 canization, solidification, plasticization and stabiliza- 1Q m m 38833-8 tion of said high molecular component, said materials oxide 1 comprising: hexamethylenamine 0.5-l .0

dibutylphthalate 25.0-35.0 calcium stearate 0.5-l .0

L540) said binder further com risin zinc oxide 3.0-20.0 p g hcxamethylenamine 0.5-1.5

- dc 8.0-l3.0 plasticizcr of polyvinylmagnesium oxi chloride resin v I 2,2-dithio-bis-benzothiazole 1.8-2.3 stabiliie rs of polyvinylchloride resin 5. A binder as claimed in claim 1 wherein said high molecular component and said materials are present in 2. A binder as claimed in claim l'in which the plastithe following proportions i Parts by weight:

cizer of the polyvinylchlor de resin consists of dibuhumdiencmmflc mhhcr 10M tylphthalate while the stabilizer thereof consists of calnovnlak p lde ydc e n 5.0 cium stearate poly inylchioridc resin 5.0 |0.0

Sulphur 35.0-40.0 3. A binder as claimed in claim 1 wherein said high zinc oxide l0.0-20.0 molecular component and said materials are present in hFXHmCIhyICMmmc l.0-l.3 the followin r0 ortions taken i art b w 'ghtg p p v n p s y calcium stcanitc 5.]

said binder further comprising: hutadicric-nitrile rubber I000 nuvoluk phenol-formaldehyde resin LO-20.0 magnesium oxide 8.0-1.3.0 polyvinylchliiridc resin 40.0-60.0 slearic acid 1.0-1.5 sulphur 1.5-2.0 coumairone resin 5.0-l0.0 zinc oxide 3.0-5.0 2.Z-diihiu'his'hcnzuthiamlc 1.8-2.3 hcxumclhylcnumine 0.5- I .0 tctriimuthylthiuram disulphide ().5-0.7 dihutylphthiilzilc 25.0-35.0 Calcium stciiriitc 0.5-l.0 3s 

2. A binder as claimed in claim 1 in which the plasticizer of the polyvinylchloride resin consists of dibutylphthalate while the stabilizer thereof consists of calcium stearate.
 3. A binder as claimed in claim 1 wherein said high molecular component and said materials are present in the following proportions, taken in parts by weight:
 4. A binder as claimed in claim 1 wherein said high molecular component and said materials are present in the following proportions in parts by weight:
 5. A binder as claimed in claim 1 wherein said high molecular component and said materials are present in the following proportions in paRts by weight: 